Field of the Invention
The present invention relates to a heat dispersion device which uniformizes heat distribution during heating of a member formed from a fiber-reinforced plastic (composite material) etc. with a heater mat for repairing or joining the member.
Description of the Related Art
A structural member constituting a fuselage of an aircraft such as a skin can be formed from a fiber-reinforced plastic (FRP) or a metal material.
When a structural member is damaged by lightning or bird striking, etc., the damaged part is removed and the void left is covered with a repair material.
The repair material is formed, for example, from a fiber-reinforced plastic similar to that used for the structural member. In that case, the repair material can be formed from an intermediate material called a prepreg. The prepreg is a material obtained by impregnating a sheet-like fiber base material with a thermosetting resin and keeping it at a low temperature so as to maintain the uncured state.
During the repair, the repair material is disposed on a recessed part of the structural member formed by removal of a damaged part, with a film-like adhesive formed from a thermosetting resin interposed therebetween, and the repair material is heated. The repair is completed when the heat applied cures the thermosetting resins constituting the repair material and the film-like adhesive and the repair material is joined to the structural member.
Here, in the manufacture of the structural member, the structural member is placed in an autoclave device and heated under pressure, to thereby mold the fiber-reinforced plastic with high quality, while in the repair of the structural member, since it is integrated with other structural members, it is difficult to place the structural member in an autoclave device.
For this reason, a heater mat (also called a heater blanket) which locally heats the repair material and the surrounding area is commonly used as a device for heating the repair material.
The heater mat is a rubber member with a built-in heat source such as a nichrome wire, and it has the flexibility to follow the shape of even the curved surface of the structural member.
The heater mat is widely used in various applications for heating a predetermined area of a member, and comes in various sizes.
Other than the heater mat, a device which applies pressure and heat using a fluid has been proposed as a heating device used for repair or joining purposes (U.S. Patent application publication No. 2009/0294053, U.S. Pat. No. 6,031,212). For example, the device according to U.S. Patent No. application publication 2009/0294053 includes a pair of chambers, each storing a fluid, for pressurizing a member held between them from both sides.
Where the thickness of a member to be repaired varies from portion to portion, or where the member is provided with a support member, an accessory, etc., the condition of heat conduction varies depending on the position in the member.
For this reason, even when the temperature of the heat generated is uniform in the plane of the heater mat, it is difficult to uniformize heat distribution, which is important for securing the repair quality.
Here, particularly according to the device of U.S. Patent application publication No. 2009/0294053, although the flow of the fluid can be expected to uniformize the heat distribution, installing the large-sized device with chambers at a position of repair is far from easy.
In this regard, the heater mat is excellent in portability and easy to install at a position of repair.
Moreover, as the heater mat is technically proven and sufficiently reliable, it is widely used.
Accordingly, there is a strong demand for a device which one can use supplementarily in combination with a heater mat to uniformize heat distribution, without introducing a new heating device that replaces a heater mat.
The same problem as that of the repair described above occurs when joining members together with an adhesive containing a thermosetting resin.
Therefore, the present invention aims to provide a device which can uniformize heat distribution using an existing heater mat in order to repair or join a member by heating the resin to cure.